Formatter for Terragrunt HCL files (#60)

* Formatter for Terragrunt HCL files

* Adding Terragrunt documentation

.pre-commit-hooks.yaml

@@ -41,3 +41,11 @@
   language: script
   files: (\.tf|\.tfvars)$
   exclude: \.terraform\/.*$
+
+- id: terragrunt_fmt
+  name: Terragrunt fmt
+  description: Rewrites all Terragrunt configuration files to a canonical format.
+  entry: terragrunt_fmt.sh
+  language: script
+  files: (\.hcl)$
+  exclude: \.terraform\/.*$

README.md

@@ -52,6 +52,7 @@ There are several [pre-commit](http://pre-commit.com/) hooks to keep Terraform c
 * `terraform_docs` - Inserts input and output documentation into `README.md`. Recommended.
 * `terraform_docs_without_aggregate_type_defaults` - Inserts input and output documentation into `README.md` without aggregate type defaults.
 * `terraform_docs_replace` - Runs `terraform-docs` and pipes the output directly to README.md
+* `terragrunt_fmt` - Rewrites all Terragrunt configuration files to a canonical format.
 
 Check the [source file](https://github.com/antonbabenko/pre-commit-terraform/blob/master/.pre-commit-hooks.yaml) to know arguments used for each hook.
 

terragrunt_fmt.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+set -e
+
+declare -a paths
+
+index=0
+
+for file_with_path in "$@"; do
+  file_with_path="${file_with_path// /__REPLACED__SPACE__}"
+
+  paths[index]=$(dirname "$file_with_path")
+
+  let "index+=1"
+done
+
+for path_uniq in $(echo "${paths[*]}" | tr ' ' '\n' | sort -u); do
+  path_uniq="${path_uniq//__REPLACED__SPACE__/ }"
+
+  pushd "$path_uniq" > /dev/null
+  terragrunt hclfmt
+  popd > /dev/null
+done